Re: ALTER TABLE ... NOREWRITE option

> Sure, and the DevOps staff would be using the EXPLAIN feature (if we had
> it).  After which they could do little anyway except complain to the ORM
> authors, who might or might not give a damn.  I don't see that there's
> enough value-added from what you suggest to justify the development
> time.

You're still thinking of a schema change as a SQL script.  ORM-based
applications usually do not run their schema changes as SQL scripts,
thus there's nothing to EXPLAIN.  Anything which assumes the presense of
a distict, user-accessible SQL script is going to leave out a large
class of our users.

However, as I said, if we had the EXPLAIN ALTER, we could use
auto-explain to log the ALTER plans (finally, a good use for
auto-explain).  So that's a workable workaround. And EXPLAIN ALTER would
offer us more flexibility than any logging option, of course.


-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com